In various industrial applications, it is necessary to attach or join one element to another. Aside from typical mechanical fasteners such as clips, screws, rivets and the like, various types of adhesives have been used, such as contact adhesives and thermally activated adhesives. For example, in some types of packages, such as those used for photographic products like paper and film, a roll of the product has been provided with opaque end disks to prevent light from reaching the edges of a strip of paper or film forming the roll. Various types of mechanical apparatus have been known for thermally attaching the end disks to the inside diameter of a core on which the roll has been wound. Such mechanical apparatus generally have been rather complex and difficult to use and maintain. Also, mechanical apparatus have tended to leave small gaps which result in the end disks not being properly attached. In other applications, thermal attachments have been made to an outside diameter of an article, using other, similarly complex apparatus. Thus, a need has existed for a more simple, yet reliable technique for thermally attaching one element around an inside or outside diameter of another element.